Transmission control device, transmission control method, reception control device, and reception control method

ABSTRACT

[Object] To provide a technology capable of performing processing on desired data in the reception-side communication device, even in the case in which a sequence number space is shared among a plurality of pieces of data transmitted from the transmission-side communication device.[Solution] Provided is a transmission control device including: a communication control unit that controls transmission of a plurality of pieces of data including respective sequence numbers; and a data generation unit that generates, as information indicating one or a plurality of pieces of data to be processed in a reception device among the plurality of pieces of data, number information indicating the sequence numbers included in the one or plurality of pieces of data to be processed. The communication control unit controls transmission of the number information to the reception device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/553,176, filed Aug. 28, 2019, which is a continuation of U.S.application Ser. No. 15/558,739, filed Sep. 15, 2017 (now U.S. Pat. No.10,439,949), which is based on PCT filing PCT/JP2016/055463, filed Feb.24, 2016, and claims priority to JP 2015-095831, filed May 8, 2015, theentire contents of each are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a transmission control device, atransmission control method, a reception control device, and a receptioncontrol method.

BACKGROUND ART

Recently, various technologies related to a wireless local area network(LAN) have become widespread. For example, as a wireless LAN technology,a protocol referred to as a block acknowledgement (hereinafter alsoreferred as “block ACK”) for sequentially transmitting a plurality ofpieces of data from a transmission-side communication device and thencollectively returning reception confirmation from a reception-sidecommunication device is used. For example, a method of performing anacknowledgement associated with the most recently transmittedtransmission sequence indicator during block acknowledgement isdisclosed (for example, refer to Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: JP 2011-125035A

DISCLOSURE OF INVENTION Technical Problem

However, even in the case in which a sequence number space is sharedamong a plurality of pieces of data transmitted from thetransmission-side communication device, it is desired to provide atechnology capable of performing processing on desired data in thereception-side communication device.

Solution to Problem

According to the present disclosure, there is provided a transmissioncontrol device including: a communication control unit that controlstransmission of a plurality of pieces of data including respectivesequence numbers; and a data generation unit that generates, asinformation indicating one or a plurality of pieces of data to beprocessed in a reception device among the plurality of pieces of data,number information indicating the sequence numbers included in the oneor plurality of pieces of data to be processed. The communicationcontrol unit controls transmission of the number information to thereception device.

According to the present disclosure, there is provided a transmissioncontrol method including: controlling transmission of a plurality ofpieces of data including respective sequence numbers; generating, asinformation indicating one or a plurality of pieces of data to beprocessed in a reception device among the plurality of pieces of data,number information indicating the sequence numbers included in the oneor plurality of pieces of data to be processed; and controllingtransmission of the number information to the reception device.

According to the present disclosure, there is provided a receptioncontrol device including: a communication control unit that controlsreception, from a transmission device, of number information indicatingsequence numbers included in one or a plurality of pieces of data to beprocessed, as information indicating the one or plurality of pieces ofdata to be processed among a plurality of pieces of data includingrespective sequence numbers; and a data acquisition unit that acquiresthe number information.

According to the present disclosure, there is provided a receptioncontrol method including: controlling reception, from a transmissiondevice, of number information indicating sequence numbers included inone or a plurality of pieces of data to be processed, as informationindicating the one or plurality of pieces of data to be processed amonga plurality of pieces of data including respective sequence numbers; andacquiring the number information.

Advantageous Effects of Invention

As described above, according to the present disclosure, even when asequence number space is shared among a plurality of pieces of datatransmitted from a transmission-side communication device, a technologycapable of performing processing on desired data in a reception-sidecommunication device is provided. Note that the effects described aboveare not necessarily limitative. With or in the place of the aboveeffects, there may be achieved any one of the effects described in thisspecification or other effects that may be grasped from thisspecification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating a configuration example of a communicationsystem common to each embodiment of the present disclosure.

FIG. 2 is a view illustrating a configuration example of a communicationdevice.

FIG. 3 is a view for describing a sequence of a transmitting operationaccording to a first embodiment of the present disclosure.

FIG. 4 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure.

FIG. 5 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure.

FIG. 6 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure.

FIG. 7 is a view illustrating a format configuration example of ageneral aggregate data frame.

FIG. 8 is a view illustrating a format configuration example of a flushframe according to the first embodiment of the present disclosure.

FIG. 9 is a view for describing a sequence of a transmitting operationaccording to a second embodiment of the present disclosure.

FIG. 10 is a view for describing a sequence of a receiving operationaccording to the second embodiment of the present disclosure.

FIG. 11 is a view illustrating a format configuration example of abeacon signal according to a second embodiment of the presentdisclosure.

FIG. 12 is a view illustrating a configuration example of flushinformation according to the second embodiment of the presentdisclosure.

FIG. 13 is a view illustrating a header configuration example to whichthe flush information of the present disclosure is added.

FIG. 14 is a view illustrating a flowchart of an operation related to atransmission-side communication device.

FIG. 15 is a view illustrating a flowchart of an operation related to areception-side communication device.

FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 17 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

FIG. 18 is a block diagram illustrating an example of a schematicconfiguration of a wireless access point.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Note that, in this description and the drawings, structural elementsthat have substantially the same function and structure are sometimesdistinguished from each other using different alphabets or numeralsafter the same reference sign. However, when there is no need inparticular to distinguish structural elements that have substantiallythe same function and structure, the same reference sign alone isattached.

The description will be given in the following order.

1. Description of problem

2. Configuration common to each embodiment

3. First embodiment

4. Second embodiment

5. Application example

6. Conclusion

1. Description of Problem

Recently, various technologies related to wireless local area network(LAN) have become widespread. For example, as a wireless LAN technology,a protocol referred to as a block ACK for sequentially transmitting aplurality of pieces of data from a transmission-side communicationdevice and then collectively returning reception confirmation from areception-side communication device is used. In such a protocol, asequence number of a start data frame requesting acknowledgement isdescribed in a request frame of the block ACK, and the reception-sidecommunication device returns the sequence number of the data framereceived from this starting sequence number in a bitmap format.

In this protocol, for example, when unicast communication is performed,a sequence number is managed for each destination communication device,and the sequence number is defined so that one is added each time a dataframe and a management frame are transmitted. On the other hand, whenmulticast communication is performed, an implementation in which asingle sequence number space is shared for a plurality of multicastcommunications without preparing a sequence number space for each of themulticast communications is possible. As an example, a method ofperforming an acknowledgement associated with the most recentlytransmitted transmission sequence indicator during a blockacknowledgement is disclosed (for example, JP 2011-125035A).

However, if a single sequence number space is shared by a plurality ofmulticast communications, a sequence number assigned to each multicastframe becomes a toothless value. Therefore, although transfer of acertain multicast frame is originally ended, because another multicastframe exists, a buffer of a reception-side communication device cannotbe flushed. As a result, a situation in which, although reception of aframe to be received by itself is completed, an arrival of a frame whichdoes not need to be received by itself is continuously waited for mayoccur. Here, flush means, for example, a process of opening data in abuffer or delivering the data to an upper layer.

When transmission of a management frame such as a beacon signal isperformed while data is being continuously transmitted from atransmission-side communication device, inconsecutiveness may occur in asequence number when a sequence number for multicast communication isalso shared for a management frame. In the method of performing anacknowledgement associated with a transmission sequence indicator asdisclosed in the above literature, because a transmission sequencenumber (TSN) is added for each request for a block acknowledgement, themethod cannot be used to flush data in internal sequence number units ofa block acknowledgement.

2. Configuration Common to Each Embodiment

In the embodiments of the present disclosure, a method for solving sucha problem is mainly proposed. Before describing each embodiment of thepresent disclosure, a configuration common to each of the embodiments ofthe present disclosure will be described first. FIG. 1 is a viewillustrating a configuration example of a communication system common toeach of the embodiments of the present disclosure. As illustrated inFIG. 1, a communication system 1 includes communication devices 10-1 to10-4 and constitutes a wireless network with the communication devices10-1 to 10-4. Although the communication system 1 includes fourcommunication devices 10 in the example illustrated in FIG. 1, thenumber of communication devices 10 included in the communication system1 is not particularly limited.

The function of each of the communication devices 10-1 to 10-4 is notlimited. For example, the communication device 10-4 may function as anaccess point. In that case, while using the communication device 10-4 asan access point, the communication devices 10-1 to 10-3 can performwireless communication under the control of the access point (thecommunication device 10-4). Alternatively, the access point may not beparticularly present.

As illustrated in FIG. 1, for example, the communication device 10-1 maycommunicate with the communication device 10-2 and the communicationdevice 10-4. The communication device 10-2 may communicate with thecommunication device 10-1, the communication device 10-3, and thecommunication device 10-4. The communication device 10-3 may communicatewith the communication device 10-2 and the communication device 10-4.The communication device 10-4 may communicate with the communicationdevice 10-1, the communication device 10-2, and the communication device10-3.

Here, as described above, when the communication device 10-4 functionsas an access point, first multicast data may be transmitted from thecommunication device 10-4 to the communication device 10-1 and thecommunication device 10-2. Also, second multicast data may betransmitted from the communication device 10-4 to the communicationdevice 10-2 and the communication device 10-3. Further, third multicastdata may be transmitted from the communication device 10-4 to thecommunication device 10-1 and the communication device 10-3.

Each of the communication devices 10-1 to 10-4 may also function as atransmission-side communication device (or a transmission controldevice) or may also function as a reception-side communication device(or a reception control device). Next, a configuration example of thecommunication device 10 will be described. FIG. 2 is a view illustratinga configuration example of the communication device 10. Here, althoughthe communication device 10-4, which serves as an access point, and theother communication devices 10-1 to 10-3 are described as having thesame configuration for convenience, the communication device 10-4 may beconnected to the Internet via a wired network when, for example, thecommunication device 10-4 functions as an access point.

As illustrated in FIG. 2, the communication device 10 includes aninterface unit 201, a transmitting buffer unit 202, a buffer managementunit (storage control unit) 203, a transmission data frame constructionunit 204, a wireless signal transmission processing unit (communicationcontrol unit) 205, a multicast transmission sequence management unit206, and a flush frame construction unit (data generation unit) 207. Aflush frame will be described below.

Further, the communication device 10 includes an access control unit208, an antenna control unit 209, and antenna elements 210A and 210B.Further, the communication device 10 includes a wireless signalreception processing unit (communication control unit) 211, a receptiondata frame extraction unit (data acquisition unit) 212, a receivingbuffer unit 213, a flush frame extraction unit 214, and a multicastreception sequence management unit 215.

The interface unit 201 includes an input unit for inputting informationfrom a user or an output unit for outputting information to the user.The transmitting buffer unit 202 stores data to be transmitted toanother communication device. The buffer management unit 203 manages ause status of an internal memory space arranged as a buffer. Thetransmission data frame construction unit 204 constructs transmissiondata having a predetermined wireless transmission data frame format. Thewireless signal transmission processing unit 205 converts a data frameto be transmitted from a baseband signal into a high-frequency signal.

The multicast transmission sequence management unit 206 manages acommunication sequence for multi cast communication. The flush frameconstruction unit 207 constructs a flush frame for multicastcommunication. The access control unit 208 controls access ofcommunication on a wireless transmission path based on a predeterminedwireless communication protocol. The antenna control unit 209 transmitsa signal on the wireless transmission path and controls an antenna thatreceives the signal from the wireless transmission path. The antennaelements 210A and 210B transmit or receive the signals as a plurality ofantenna elements.

The wireless signal reception processing unit 211 converts ahigh-frequency signal received via the antenna into a baseband signal.The reception data frame extraction unit 212 extracts data from thebaseband signal as a predetermined data frame. The receiving buffer unit213 temporarily stores received user data until a predetermined unit ofdata that can be output to the interface unit is collected. The flushframe extraction unit 214 extracts the flush frame according to thepresent disclosure from the received baseband signal. The multicastreception sequence management unit 215 manages the reception sequence ofthe multicast communication.

3. First Embodiment

Next, the first embodiment of the present disclosure will be described.FIG. 3 is a view for describing a sequence of a transmitting operationaccording to the first embodiment of the present disclosure. Asillustrated in FIG. 3, in the communication system 1, three flows ofmulticast communication MA, MB, and MC are performed. Pieces ofmulticast data MA #1 to MA #4 are stored as the multicast communicationMA in the transmitting buffer, Pieces of multicast data MB #1 and MB #2are stored as the multicast communication MB in the transmitting buffer,and pieces of multicast data MC #1 and MC #2 are stored as the multicastcommunication MC in the transmitting buffer.

In the transmission-side communication device, the multicasttransmission sequence management unit 206 adds a sequence number formulticasting to the above multicast data, and the wireless signaltransmission processing unit 205 controls transmission of the multicastdata. First, the transmission-side communication device adds a sequencenumber SN:1 to the multicast data MA #1 and transmits the multicast dataMA #1, adds a sequence number SN:2 to the multicast data MB #1 andtransmits the multicast data MB #1, and adds a sequence number SN:3 tothe multicast data MC #1 and transmits the multicast data MC #1. Asdescribed above, although an individual sequence number is added to eachpiece of multicast data to be transmitted, the sequence number becomesan inconsecutive value for each flow of multicast communication.

Further, the transmission-side communication device adds a sequencenumber SN:4 to the multicast data MA #2 and transmits the multicast dataMA #2, adds a sequence number SN:5 to the multicast data MA #3 andtransmits the multicast data MA #3, adds a sequence number SN:6 to themulticast data MB #2 and transmits the multicast data MB #2, adds asequence number SN:7 to the multicast data MA #4 and transmits themulticast data MA #4, and adds a sequence number SN:8 to the multicastdata MC #2 and transmits the multicast data MC #2.

Here, in the transmission-side communication device, for example, an endof the transmission of the multicast data stored in the transmittingbuffer is a trigger for the wireless signal transmission processing unit205 to control transmission of the flush frame according to the presentdisclosure. The flush frame is information (number information)indicating one or a plurality of pieces of data to be processed in thereception-side communication device among the multicast data andindicates a sequence number included in each of the one or plurality ofpieces of data to be processed.

The wireless signal transmission processing unit 205 may controltransmission by multicast communication of the flush frame. Further, theflush frame may be defined for each flow of the multicast communication.For example, as illustrated in FIG. 3, in the transmission-sidecommunication device, the flush frame construction unit 207 generates aflush frame: Flash A of the multicast communication MA, a flush frame:Flash B of the multicast communication MB, and a flush frame: Flash C ofthe multicast communication MC.

When the flush frames are subject to multicast transmission, apredetermined sequence number may not be added to the flush frames, buta predetermined sequence number may be added thereto as a type ofmanagement frame and sent. Specifically, as illustrated in FIG. 3, asequence number SN:9 is added to Flash A, a sequence number SN:10 isadded to Flash B, and a sequence number SN:10 is added to Flash C. Then,the wireless signal transmission processing unit 205 controlstransmission of the flush frames.

According to the transmission-side communication device, even when asequence number space is shared among the plurality of pieces ofmulticast data transmitted from the transmission-side communicationdevice, predetermined processing on desired data can be performed in thereception-side communication device.

In the example illustrated in FIG. 3, each of a plurality of data framestransmitted from the transmission-side communication device to thereception-side communication device is described independently. However,aggregation processing may be performed on the plurality of data framesas necessary in the transmission-side communication device, and theplurality of data frames may be combined as a single physical layer(PHY) burst and transmitted to the reception-side communication device.

FIG. 4 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure. FIG. 4illustrates a receiving operation of the reception-side communicationdevice performing the multicast communication MA and illustrates anoperation of extracting only multicast data to be processed frommulticast data transmitted, with inconsecutive sequence numbers attachedthereto, from the transmission-side communication device andreconstructing the data. First, multicast data received by the multicastcommunication is stored in the receiving buffer unit 213.

For example, as illustrated in FIG. 4, in the reception-sidecommunication device, the wireless signal reception processing unit 211controls reception of the pieces of multicast data MA-1 to MA-4 relatedto the multicast communication MA, and the buffer management unit 203stores the pieces of multicast data MA-1 to MA-4 to be received fromreception data extracted by the reception data frame extraction unit 212in the receiving buffer unit 213. After the multicast communicationends, in the reception-side communication device, the wireless signalreception processing unit 211 controls reception of a flush frametransmitted from the transmission-side communication device.

As illustrated in FIG. 4, it is assumed that the flush frame: Flash A isreceived in the reception-side communication device. The multicastreception sequence management unit 215 may acquire the flush frame andspecify the pieces of multicast data MA-1 to MA-4 to which sequencenumbers SN:1, SN:4, SN:5, and SN:7 indicated by the flush frame areattached as multicast data to be processed.

According to the configuration of the reception-side communicationdevice, even when a sequence number space is shared among the pluralityof piece of multicast data transmitted from the transmission-sidecommunication device, predetermined processing on desired data can beperformed in the reception-side communication device. Further, in thereception-side communication device, predetermined processing may beperformed on the specified pieces of multicast data MA-1 to MA-4 to beprocessed.

The predetermined processing is not limited. For example, in thereception-side communication device, the multicast reception sequencemanagement unit 215 may determine whether the pieces of multicast dataMA-1 to MA-4 to be processed are received with reference to the flushframe. Then, when it is determined that the pieces of multicast dataMA-1 to MA-4 to be processed are received, the buffer management unit203 may deliver the pieces of multicast data MA-1 to MA-4 to beprocessed from the receiving buffer unit 213 to an upper layerapplication (the interface unit 201).

Further, for example, when it is determined that the pieces of multicastdata MA-1 to MA-4 to be processed are received, the buffer managementunit 203 may flush the pieces of multicast data MA-1 to MA-4 to beprocessed from the receiving buffer unit 213.

Further, the multicast reception sequence management unit 215 maydetermine whether reception of the pieces of multicast data MA-1 to MA-4to be processed is completed within a predetermined period withreference to the flush frame. Further, when it is determined that thereception of the pieces of multicast data MA-1 to MA-4 to be processedis not completed even after the lapse of the predetermined period, thebuffer management unit 203 may flush received data to be processed amongthe pieces of multicast data MA-1 to MA-4 to be processed from thereceiving buffer unit 213.

FIG. 5 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure. FIG. 5illustrates a receiving operation of the reception-side communicationdevice performing the multicast communication MB and illustrates anoperation of extracting only multicast data to be processed frommulticast data transmitted, with inconsecutive sequence numbers attachedthereto, from the transmission-side communication device andreconstructing the data. First, multicast data received by the multicastcommunication is stored in the receiving buffer unit 213.

For example, as illustrated in FIG. 5, in the reception-sidecommunication device, the wireless signal reception processing unit 211controls reception of the pieces of multicast data MB-1 and MB-2 relatedto the multicast communication MB, and the buffer management unit 203stores the pieces of multicast data MB-1 and MB-2 to be received fromreception data extracted by the reception data frame extraction unit 212in the receiving buffer unit 213. After the multicast communicationends, in the reception-side communication device, the wireless signalreception processing unit 211 controls reception of the flush frametransmitted from the transmission-side communication device.

As illustrated in FIG. 5, it is assumed that the flush frame: Flash B isreceived in the reception-side communication device. The multicastreception sequence management unit 215 may acquire the flush frame andspecify the pieces of multicast data MB-1 and MB-2 to which sequencenumbers SN:2 and SN:6 indicated by the flush frame are attached asmulticast data to be processed.

According to the configuration of the reception-side communicationdevice, even when a sequence number space is shared among the pluralityof multicast data transmitted from the transmission-side communicationdevice, predetermined processing on desired data can be performed in thereception-side communication device. Further, in the reception-sidecommunication device, predetermined processing may be performed on thespecified pieces of multicast data MB-1 and MB-2 to be processed.

The predetermined processing is not limited. For example, in thereception-side communication device, the multicast reception sequencemanagement unit 215 may determine whether the pieces of multicast dataMB-1 and MB-2 to be processed are received with reference to the flushframe. Then, when it is determined that the pieces of multicast dataMB-1 and MB-2 to be processed are received, the buffer management unit203 may deliver the pieces of multicast data MB-1 and MB-2 to beprocessed from the receiving buffer unit 213 to an upper layerapplication (the interface unit 201).

Further, for example, when it is determined that the pieces of multicastdata MB-1 and MB-2 to be processed are received, the buffer managementunit 203 may flush the pieces of multicast data MB-1 and MB-2 to beprocessed from the receiving buffer unit 213.

Further, the multicast reception sequence management unit 215 maydetermine whether reception of the pieces of multicast data MB-1 andMB-2 to be processed is completed within a predetermined period withreference to the flush frame. Further, when it is determined that thereception of the pieces of multicast data MB-1 and MB-2 to be processedis not completed even after the lapse of the predetermined period, thebuffer management unit 203 may flush received data to be processed ofthe pieces of multicast data MB-1 and MB-2 to be processed from thereceiving buffer unit 213.

FIG. 6 is a view for describing a sequence of a receiving operationaccording to the first embodiment of the present disclosure. FIG. 6illustrates a receiving operation of the reception-side communicationdevice performing the multicast communication MC and illustrates anoperation of extracting only multicast data to be processed frommulticast data transmitted, with inconsecutive sequence numbers attachedthereto, from the transmission-side communication device andreconstructing the data. First, multicast data received by the multicastcommunication is stored in the receiving buffer unit 213.

For example, as illustrated in FIG. 6, in the reception-sidecommunication device, the wireless signal reception processing unit 211controls reception of the pieces of multicast data MC-1 and MC-2 relatedto the multicast communication MC, and the buffer management unit 203stores the pieces of multicast data MC-1 and MC-2 to be received fromreception data extracted by the reception data frame extraction unit 212in the receiving buffer unit 213. After the multicast communicationends, in the reception-side communication device, the wireless signalreception processing unit 211 controls reception of the flush frametransmitted from the transmission-side communication device.

As illustrated in FIG. 6, it is assumed that the flush frame: Flash C isreceived in the reception-side communication device. The multicastreception sequence management unit 215 may acquire the flush frame andspecify the pieces of multicast data MC-1 and MC-2 to which sequencenumbers SN:3 and SN:8 indicated by the flush frame are attached asmulticast data to be processed.

According to the configuration of the reception-side communicationdevice, even when a sequence number space is shared among the pluralityof pieces of multicast data transmitted from the transmission-sidecommunication device, predetermined processing on desired data can beperformed in the reception-side communication device. Further, in thereception-side communication device, predetermined processing may beperformed on the specified pieces of multicast data MC-1 and MC-2 to beprocessed.

The predetermined processing is not limited. For example, in thereception-side communication device, the multicast reception sequencemanagement unit 215 may determine whether the pieces of multicast dataMC-1 and MC-2 to be processed are received with reference to the flushframe. Then, when it is determined that the pieces of multicast dataMC-1 and MC-2 to be processed are received, the buffer management unit203 may deliver the pieces of multicast data MC-1 and MC-2 to beprocessed from the receiving buffer unit 213 to an upper layerapplication (the interface unit 201).

Further, for example, when it is determined that the pieces of multicastdata MC-1 and MB-C to be processed are received, the buffer managementunit 203 may flush the pieces of multicast data MC-1 and MC-2 to beprocessed from the receiving buffer unit 213.

Further, the multicast reception sequence management unit 215 maydetermine whether reception of the pieces of multicast data MC-1 andMC-2 to be processed is completed within a predetermined period withreference to the flush frame. Further, when it is determined that thereception of the pieces of multicast data MC-1 and MC-2 to be processedis not completed even after the lapse of the predetermined period, thebuffer management unit 203 may flush received data to be processed ofthe pieces of multicast data MC-1 and MC-2 to be processed from thereceiving buffer unit 213.

Although the case in which a flush frame of a single flow is received isillustrated in FIGS. 4 to 6, it is also assumed that a flush frame foreach flow is received. In such a case, the multicast reception sequencemanagement unit 215 may determine whether one or a plurality of piecesof data to be processed related to all flows are received with referenceto a flush frame for each of the flows. Also, when it is determined thatthe one or plurality of pieces of data to be processed related to all ofthe flows are received, the buffer management unit 203 may flush the oneor plurality of pieces of data to be processed related to all of theflows from the receiving buffer unit 213.

The multicast reception sequence management unit 215 may determinewhether one or a plurality of pieces of data to be processed related tosome of the flows are received with reference to the flush frame foreach of the flows. When it is determined that the one or plurality ofpieces of data to be processed related to some of the flows arereceived, the buffer management unit 203 may flush the one or pluralityof pieces of data to be processed related to some of the flows from thereceiving buffer unit 213 and may not flush the one or plurality ofpieces of data to be processed related to remaining flows from thereceiving buffer unit 213.

FIG. 7 is a view illustrating a format configuration example of ageneral aggregate data frame. In the example illustrated in FIG. 7, as asingle PHY burst, a MAC Protocol Data Unit (MPDU), which is a pluralityof pieces of user data, is configured as an aggregated MPDU (A-MPDU)sub-frame. The A-MPDU sub-frame has an MPDU delimiter, an MPDU, andpadding.

Each MPDU has a MAC header, a frame body, and a frame check sequence(FCS), and a fragment number and a sequence number are stored in asequence control part of the MAC header. That is, a single sequencenumber is added to a single piece of user data included in a singleMPDU, and the piece of user data is transferred.

FIG. 8 is a view illustrating a format configuration example of theflush frame according to the first embodiment of the present disclosure.The flush frame is transmitted as a management frame handled as a singleMPDU, a flush control field is configured as a payload body in the MACheader, and an FCS is added thereto. The flush control field includes acontrol parameter including various pieces of control information, aflow ID for identifying a flow, a start sequence number indicating thestart of a sequence number to be flushed, a sequence number bitmapindicating a predetermined number starting from the start sequencenumber, and the like.

The first embodiment of the present disclosure has been described above.According to the first embodiment of the present disclosure, even whenunreachable multicast data is present, a sequence number thereof may bespecified. Here, the reception-side communication device may returnblock acknowledgement to the transmission-side communication device asnecessary and receive re-transmitted data.

Further, an example in which a flush frame is transmitted with an end oftransmission of a series of data stored in the transmitting buffer unit202 as a trigger has been described above. However, the trigger for thetransmission of the flush frame is not particularly limited. Forexample, the trigger for the transmission of the flush frame may be apredetermined data transmission being performed or a lapse of apredetermined time after first multicast data is transmitted.

Further, an operation of a communication device that functions as atransmission-side communication device and an operation of acommunication device that functions as a reception-side communicationdevice among the communication devices 10-1 to 10-4 have been separatelydescribed above. However, each of the communication devices 10-1 to 10-4may have the functions of both the transmission-side communicationdevice and the reception-side communication device or may have afunction of only one of the transmission-side communication device andthe reception-side communication device.

4. Second Embodiment

Next, the second embodiment of the present disclosure will be described.FIG. 9 is a view for describing a sequence of a transmitting operationaccording to the second embodiment of the present disclosure. In thesecond embodiment of the present disclosure, when a transmission-sidecommunication device is operating as an access point that transmits apredetermined beacon signal, number information (hereinafter, alsoreferred to as “flush information”) is added to the beacon signal, and areception-side communication device is notified of the flush informationat a predetermined cycle by the beacon signal. Referring to FIG. 9,multicast communication MD is performed from the transmission-sidecommunication device, and a flow of the multicast communication MD ispresent.

Here, although an access point of a wireless network transmits a beaconsignal at a predetermined cycle, the beacon signal may be present as amanagement frame. Therefore, the multicast transmission sequencemanagement unit 206 adds a predetermined sequence number to a beaconsignal, and the wireless signal transmission processing unit 205controls transmission of the beacon signal to which the sequence numberis added. Here, a sequence number SN:1 is added to a beacon signal andthe beacon signal is transmitted, a sequence number SN:2 is added tomulticast data MD-1 and the multicast data MD-1 is transmitted, and asequence number SN:3 is added to multicast data MD-2 and the multicastdata MD-2 is transmitted.

A sequence number SN:4 is added to another management frame and theother management frame is transmitted, a sequence number SN:5 is addedto multicast data MD-3 and the multicast data MD-3 is transmitted, asequence number SN:6 is added to multicast data MD-4 and the multicastdata MD-4 is transmitted, and a sequence number SN:7 is added tomulticast data MD-5 and the multicast data MD-5 is transmitted. Also, asequence number SN:8 is added to another management frame and the othermanagement frame is transmitted. Then, flush information: Flash D of thepresent disclosure is added to the next beacon signal and the beaconsignal is transmitted.

FIG. 10 is a view for describing a sequence of a receiving operationaccording to the second embodiment of the present disclosure. FIG. 10illustrates a receiving operation of the reception-side communicationdevice performing the multicast communication MD and illustrates anoperation of reconstructing data by extracting only multicast data to beprocessed from data received by the reception data frame extraction unit212 from multicast data sent from the transmission-side communicationdevice as inconsecutive sequence numbers and reconstructing the data.First, the multicast data to be received, received by the multicastcommunication, is stored in the receiving buffer unit 213.

As illustrated in FIG. 10, it is assumed that a beacon signal in whichthe flush information: Flash D is set is received in the reception-sidecommunication device. The multicast reception sequence management unit215 may extract the flush information: Flash D from the beacon signaland specify the pieces of multicast data MA-1 to MA-5 to which thesequence numbers SN:2, SN3, SNS, SN6 and SN7 indicated by the flushinformation are attached as multicast data to be processed.

As in the first embodiment of the present disclosure, according to theconfiguration of the reception-side communication device, even when asequence number space is shared among the plurality of pieces ofmulticast data transmitted from the transmission-side communicationdevice, predetermined processing can be performed on desired data in thereception-side communication device. Further, in the reception-sidecommunication device, predetermined processing may be performed on thespecified multicast data MA-1 to MA-5 to be processed. As in the firstembodiment of the present disclosure, the predetermined processing isnot limited.

FIG. 11 illustrates a format configuration example of a beacon signalaccording to the second embodiment of the present disclosure. Asillustrated in FIG. 11, a beacon signal is transmitted as a managementframe handled as a single MPDU and is configured as an FCS in a payloadof the beacon signal in a MAC header. The beacon payload includesinformation for setting various parameters, and flush informationaccording to the second embodiment may also be included therein.

FIG. 12 is a view illustrating a configuration example of the flushinformation according to the second embodiment of the presentdisclosure. The flush information includes an element type fordesignating an element type, a length indicating a length of the flushinformation, a control parameter including various pieces of controlinformation, a flow ID for identifying a flow, a start sequence numberindicating a start of a sequence number to be flushed, and a sequencenumber bit map indicating a predetermined number starting from the startsequence number.

FIG. 13 is a view illustrating a header configuration example to whichthe flush information of the present disclosure is added. In the exampleillustrated in FIG. 13, a flush control header is added in front of orthe end of an A-MPDU sub-frame in which an MPDU, which is a plurality ofpieces of user data, is aggregated as a single PHY burst.

The flush control header includes a control parameter including variouspieces of control information, a flow ID for identifying a flow, a startsequence number indicating a start of a sequence number to be flushed,and flush information (for example, a sequence number bitmap indicatinga predetermined number starting from the start sequence number).Further, a header check sequence for determining whether an error occursin the header portion may be added to the flush control header.

FIG. 14 is a view illustrating a flowchart of an operation related to atransmission-side communication device. The transmission-sidecommunication device determines whether data to be transmitted isaccepted from an application device connected thereto via an interface(S101), and when the data to be transmitted is accepted, stores the datain a transmitting buffer (S102). Further, the transmission-sidecommunication device grasps a use status of a wireless transmission path(S103), and, when the transmission path is available at a target beacontransmission time: TBTT (S104), acquires a beacon parameter (S105).

Then, the transmission-side communication device sets a transmissionsequence number of a beacon signal which is a management frame (S106),transmits the beacon signal for which the transmission sequence numberis set (S107), and saves the latest sequence number added to thetransmitted beacon signal (S108).

If management data is present in the transmitting buffer (S109), thetransmission-side communication device acquires transmission sequencenumber information (S110), transmits management data, in which a valueobtained by incrementing the latest sequence number is set, as a frame(S111), and saves the latest sequence number added to the transmittedmanagement frame (S112). Here, when multicasting or broadcasting themanagement data, the frame is transmitted using a sequence number formulticasting.

Then, when transmission data of multicast communication is stored in thetransmitting buffer (S113), the transmission-side communication deviceacquires sequence number information for multicasting (S114), transmitsmulticast data, for which a value obtained by incrementing the sequencenumber is set, as a frame (S115), and saves the latest sequence numberadded to the transmitted management frame (S116).

Further, the transmission-side communication device saves the sequencenumber in association with a transmission sequence number correspondingto a flow for the multicast communication (S117). That is, when a flowof a plurality of multicast communications is shared, a value of asequence number transmitted for each of the flows of the multicast issaved.

Then, when transmission of a series of multicast communications iscompleted for each of the multicast flows (S118), the transmission-sidecommunication device checks the use of the flush frame of the presentdisclosure (S119), and when corresponding to the flush frame (S120), thetransmission-side communication device acquires information of thetransmitted sequence number corresponding to the flow of the multicastcommunication (S121) and constructs a flush frame as a frame ofmanagement data (S122). Although an example of constructing a flushframe is shown here, when a beacon signal in which flush information isset is transmitted, a beacon signal in which flush information is setmay be constructed.

If data to be unicast-transmitted is present in the transmitting buffer(S123), the transmission-side communication device acquires atransmission sequence number corresponding to a destinationreception-side communication device (S124), transmits unicast data, inwhich a value obtained by incrementing the sequence number is set, as aframe (S125), and saves the latest sequence number corresponding to thereception-side communication device (S126).

Further, when the transmission-side communication device receives an ACKframe addressed to itself (S127), if it is determined that unreachabledata is present therein from information of the ACK frame (S128), thetransmission-side communication device extracts the unreachable datafrom the transmitting buffer (S129) and re-transmits the data (S130). Onthe other hand, if it is determined that unreachable data is not present(if receipt of all data is confirmed), the transmission-sidecommunication device deletes data related to the sequence of themulticast communication from the transmitting buffer (S131).

FIG. 15 is a view illustrating a flowchart of an operation related tothe reception-side communication device. When the reception-sidecommunication device receives (unicast) data addressed to itself (S151),the reception-side communication device acquires reception sequencenumber information for unicast (S152), and if it is determined thatunreachable data is received from the value for the unicast sequencenumber included in the received data (S153), the reception-sidecommunication device stores the received data in the receiving buffer(S154).

For example, there is a case in which the reception-side communicationdevice determines that additional received data is not sent frominformation such as More Data Bit in header information of a data frame.In such a case, the reception-side communication device determines thatreception of a series of data is completed (S155), delivers the data toan upper layer (S156), and flushes data from the start sequence numberto the latest sequence number from the receiving buffer (S157). On theother hand, when the reception of the series of data is not completed,the reception-side communication device activates a reception unicasttimer (S158).

When multicast data addressed to itself is received in thereception-side communication device (S159), the reception-sidecommunication device acquires reception sequence number information formulticast (S160). Next, when it is determined that unreachable data isreceived from a value of a multicast sequence number included in thereceived data (S161), the reception-side communication device stores thereceived data in the receiving buffer (S162), and updates information ofthe reception sequence number for multicast (S163). Here, when thereception is completed with inconsecutive sequence numbers (S164), thereception-side communication device activates a reception multicasttimer (S165).

On the other hand, when all data of the multicast communication isreceived with consecutive sequence numbers, the reception-sidecommunication device, for example, determines that a series of thereceived data is completed from information such as More Data Bit in theheader information of the data frame in some cases. In such a case, thereception-side communication device shifts the operation to S171.

When a flush frame of multicast communication addressed to itself isreceived in the reception-side communication device (S166), thereception-side communication device extracts a list of maps of sequencenumbers that can be flushed in the multicast communication frominformation of flush sequence numbers of the multicast communication(S167). Then, the reception-side communication device temporarily savesthe sequence numbers (S168) and acquires a list of received numbers ofthe multicast communication received by itself (S169).

Here, if reception of all of the series of sequence numbers of themulticast communication is completed (S170), the reception-sidecommunication device may perform a process of delivering the series ofmulticast data to an upper layer (S171). When the multicast data isdelivered to the upper layer, for example, control may be performed suchthat image information is output to a display connected thereto via aninterface. Further, the reception-side communication device flushes thereceived data from the receiving buffer of the sequence numbers (S172).

If reception setting of another multicast communication is not performed(S173), the reception-side communication device flushes received datafrom the start sequence number up to the latest sequence number (S174).Alternatively, if a flushable sequence number of a frame to be usedother than the multicast communication is added to the flush frame, thereception-side communication device may flush the frame from thereceiving buffer.

On the other hand, it is assumed that data of a series of sequencenumbers of the multicast communication is not available. In such a case,when the reception multicast timer times out (S175), the reception-sidecommunication device displays a reception error of the multicast frame(S176) and reads a series of sequence numbers of the multicastcommunication which is temporarily saved (S177). Then, thereception-side communication device shifts the operation to S172 andflushes received data corresponding to the sequence numbers from thereceiving buffer.

When the reception unicast timer times out (S178), the reception-sidecommunication device displays a reception error of the unicast frame(S179). Then, the reception-side communication device shifts theoperation to S174 and flushes the received data from the start sequencenumber up to the latest sequence number from the receiving buffer.

5. Application Examples

The technology according to the present disclosure is applicable tovarious products. In one example, the communication device 10 may beimplemented as a mobile terminal such as smartphones, tablet personalcomputers (PCs), notebook PCs, portable game terminals, or digitalcameras, a fixed-type terminal such as television receivers, printers,digital scanners, or network storages, or a car-mounted terminal such ascar navigation devices. In addition, the communication device 10 may beimplemented as a terminal (also referred to as machine typecommunication (MTC) terminal) which performs machine-to-machine (M2M)communication, such as smart meters, vending machines, remote monitoringdevices, and point of sale (POS) terminals. Furthermore, thecommunication device 10 may be a wireless communication module mountedin such terminals (e.g., integrated circuit modules configured in onedie).

On the other hand, in one example, the communication control device maybe implemented as a wireless LAN access point (also referred to as awireless base station) having or not having a router function. Inaddition, the communication control device may be implemented as amobile wireless LAN router. Furthermore, the communication controldevice may be a wireless communication module mounted on such devices(e.g., integrated circuit modules configured in one die).

[5-1. First Application Example]

FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure can be applied. The smartphone 900 is configured to include aprocessor 901, a memory 902, a storage 903, an externally connectedinterface 904, a camera 906, a sensor 907, a microphone 908, an inputdevice 909, a display device 910, a speaker 911, a wirelesscommunication interface 913, an antenna switch 914, an antenna 915, abus 917, a battery 918, and an auxiliary controller 919.

The processor 901 may be, in one example, a central processing unit(CPU) or a system on chip (SoC), and controls functions of anapplication layer and other layers of the smartphone 900. The memory 902includes a random access memory (RAM) and a read only memory (ROM), andstores programs executed by the processor 901 and data. The storage 903can include a storage medium such as a semiconductor memory or a harddisk. The externally connected interface 904 is an interface forconnecting an externally attached device such as a memory card or auniversal serial bus (USB) device to the smartphone 900.

The camera 906 has, in one example, an image sensor such as a chargecoupled device (CCD) or a complementary metal oxide semiconductor(CMOS), and generates a captured image. The sensor 907 can include asensor group including, in one example, a positioning sensor, a gyrosensor, a geomagnetic sensor, an acceleration sensor, and the like. Themicrophone 908 converts voice input to the smartphone 900 into an audiosignal. The input device 909 includes, in one example, a touch sensorthat detects touches on a screen of the display device 910, a key pad, akeyboard, buttons, switches, and the like, and accepts an operation orinformation input from a user. The display device 910 has a screen suchas a liquid crystal display (LCD) or an organic light emitting diode(OLED) display, and displays an output image of the smartphone 900. Thespeaker 911 converts an audio signal output from the smartphone 900 intovoice.

The wireless communication interface 913 supports one or more wirelessLAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, and had, andexecutes wireless LAN communication. The wireless communicationinterface 913 can communicate with other devices via a wireless LANaccess point in the infrastructure mode. In addition, the wirelesscommunication interface 913 can directly communicate with other devicesin a direct communication mode such as an ad hoc mode, and Wi-Fi Direct(registered trademark). In Wi-Fi Direct mode, unlike ad hoc mode, one oftwo terminals operates as an access point, but communication isperformed directly between the terminals. The wireless communicationinterface 913 can typically include a baseband processor, a radiofrequency (RF) circuit, a power amplifier, and the like. The wirelesscommunication interface 913 may be a single-chip module on which amemory for storing a communication control program, a processor forexecuting the program, and a relevant circuit are integrated. Thewireless communication interface 913 may support other types of wirelesscommunication schemes such as a short-range wireless communicationscheme, a close proximity wireless communication scheme, or a cellularcommunication scheme, in addition to the wireless LAN scheme. Theantenna switch 914 switches a connection destination of the antenna 915among a plurality of circuits (e.g., circuits for different wirelesscommunication schemes) included in the wireless communication interface913. The antenna 915 has a single antenna element or a plurality ofantenna elements (e.g., a plurality of antenna elements constituting aMIMO antenna), and is used for transmission and reception of a wirelesssignal through the wireless communication interface 913.

Moreover, the configuration of the smartphone 900 is not limited to theexample of FIG. 16, and may include a plurality of antennas (e.g., anantenna for a wireless LAN and an antenna for a proximity wirelesscommunication scheme). In this case, the antenna switch 914 may beomitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the externally connected interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 913, and the auxiliarycontroller 919 to one another. The battery 918 supplies electric powerto each of the blocks of the smartphone 900 illustrated in FIG. 16 via apower supply line partially indicated by dashed lines in the figure. Theauxiliary controller 919 operates the required minimum functions of thesmartphone 900, in one example, in the sleep mode.

In the smartphone 900 illustrated in FIG. 16, the wireless signaltransmission processing unit 205, the access control unit 208, and thewireless signal reception processing unit 211 described with referenceto FIG. 2 may be implemented in a wireless communication interface 913.Also, at least some of the wireless signal transmission processing unit205, the access control unit 208, and the wireless signal receptionprocessing unit 211 may be implemented in a processor 901 or anauxiliary controller 919. For example, the wireless signal transmissionprocessing unit 205 converts a baseband signal into a high-frequencysignal. The access control unit 208 controls access of communication onthe wireless transmission path according to a predetermined wirelesscommunication protocol. Further, the wireless signal receptionprocessing unit 211 extracts the baseband signal from the high-frequencysignal.

Moreover, the smartphone 900 may operate as a wireless access point(software AP) by the processor 901 executing an access point function atthe application level. In addition, the wireless communication interface913 may have the wireless access point function.

[5-2. Second Application Sample]

FIG. 17 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technologyaccording to the present disclosure can be applied. The car navigationdevice 920 is configured to include a processor 921, a memory 922, aglobal positioning system (GPS) module 924, a sensor 925, a datainterface 926, a content player 927, a storage medium interface 928, aninput device 929, a display device 930, a speaker 931, a wirelesscommunication interface 933, an antenna switch 934, an antenna 935, anda battery 938.

The processor 921 may be, in one example, a CPU or SoC, and controls anavigation function and other functions of the car navigation device920. The memory 922 includes a RAM and a ROM, and stores programsexecuted by the processor 921 and data.

The GPS module 924 measures the position (e.g., latitude, longitude, andaltitude) of the car navigation device 920 using GPS signals receivedfrom a GPS satellite. The sensor 925 can include a sensor groupincluding, in one example, a gyro sensor, a geomagnetic sensor, and abarometric pressure sensor. The data interface 926 is connected to, inone example, an in-vehicle network 941 via a terminal that is notillustrated, and acquires data generated on the vehicle side such as carspeed data.

The content player 927 reproduces the content stored in a storage medium(e.g., CD or DVD) inserted into the storage medium interface 928. Theinput device 929 includes, in one example, a touch sensor that detectstouches on a screen of the display device 930, buttons, switches, andthe like, and accepts an operation or information input from the user.The display device 930 has a screen such as an LCD or an OLED display,and displays a navigation function or an image of content. The speaker931 outputs sound of the navigation function or the content to bereproduced.

The wireless communication interface 933 supports one or more wirelessLAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, and 11ad, andexecutes wireless LAN communication. The wireless communicationinterface 933 can communicate with other devices via a wireless LANaccess point in the infrastructure mode. In addition, the wirelesscommunication interface 933 can directly communicate with other devicesin a direct communication mode, such as an ad hoc mode and Wi-Fi Direct.The wireless communication interface 933 can typically have a basebandprocessor, an RF circuit, a power amplifier, and the like. The wirelesscommunication interface 933 may be a single-chip module on which amemory for storing a communication control program, a processor forexecuting the program, and a relevant circuit are integrated. Thewireless communication interface 933 may support other types of wirelesscommunication schemes such as a short-range wireless communicationscheme, a close proximity wireless communication scheme, or a cellularcommunication scheme, in addition to the wireless LAN scheme. Theantenna switch 934 switches a connection destination of the antenna 935among a plurality of circuits included in the wireless communicationinterface 933. The antenna 935 has a single antenna element or aplurality of antenna elements, and is used for transmission andreception of a wireless signal from the wireless communication interface933.

Moreover, the configuration of the car navigation device 920 is notlimited to the example of FIG. 17, and may include a plurality ofantennas. In this case, the antenna switch 934 may be omitted from theconfiguration of the car navigation device 920.

The battery 938 supplies electric power to each of the blocks of the carnavigation device 920 illustrated in FIG. 17 via a power supply linepartially indicated by a dashed line in the figure. In addition, thebattery 938 accumulates electric power supplied from the vehicle side.

In the car navigation device 920 illustrated in FIG. 17, the wirelesssignal transmission processing unit 205, the access control unit 208,and the wireless signal reception processing unit 211 described withreference to FIG. 2 may be implemented in a wireless communicationinterface 933. Also, at least some of the wireless signal transmissionprocessing unit 205, the access control unit 208, and the wirelesssignal reception processing unit 211 may be implemented in a processor921. For example, the wireless signal transmission processing unit 205converts a baseband signal into a high-frequency signal. The accesscontrol unit 208 controls access of communication on the wirelesstransmission path according to a predetermined wireless communicationprotocol. Further, the wireless signal reception processing unit 211extracts the baseband signal from the high-frequency signal.

Further, the wireless communication interface 933 may operate as theabove-described communication control device and may provide wirelessconnection to a terminal carried by a user who rides in a vehicle.

Further, the technology according to the present disclosure may beimplemented as an in-vehicle system (or vehicle) 940 including one ormore blocks of the above-described car navigation device 920, thein-vehicle network 941, and a vehicle-side module 942. The vehicle-sidemodule 942 generates vehicle-side data such as vehicle speed, enginerpm, or failure information, and outputs the generated data to thein-vehicle network 941.

[5-3. Third Application Example]

FIG. 18 is a block diagram illustrating an example of a schematicconfiguration of a wireless access point 950 to which the technologyaccording to the present disclosure can be applied. The wireless accesspoint 950 is configured to include a controller 951, a memory 952, aninput device 954, a display device 955, a network interface 957, awireless communication interface 963, an antenna switch 964, and anantenna 965.

The controller 951 may be, in one example, a CPU or a digital signalprocessor (DSP), and operates various functions (e.g., accessrestriction, routing, encryption, firewall, and log management) of theInternet Protocol (IP) layer and higher layers of the wireless accesspoint 950. The memory 952 includes a RAM and a ROM, and stores a programto be executed by the controller 951 and various kinds of control data(e.g., a terminal list, a routing table, an encryption key, securitysettings, and a log).

The input device 954 includes, in one example, a button or a switch, andaccepts an operation from a user. The display device 955 includes an LEDlamp or the like, and displays operation status of the wireless accesspoint 950.

The network interface 957 is a wired communication interface thatconnects the wireless access point 950 to the wired communicationnetwork 958. The network interface 957 may include a plurality ofconnection terminals. The wired communication network 958 may be a LANsuch as Ethernet (registered trademark) or a wide area network (WAN).

The wireless communication interface 963 supports one or more wirelessLAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, and 11ad, andprovides wireless connection to a neighboring terminal by functioning asan access point. The wireless communication interface 963 can typicallyhave a baseband processor, an RF circuit, a power amplifier, and thelike. The wireless communication interface 963 may be a single-chipmodule on which a memory for storing a communication control program, aprocessor for executing the program, and a relevant circuit areintegrated. The antenna switch 964 switches a connection destination ofthe antenna 965 among a plurality of circuits included in the wirelesscommunication interface 963. The antenna 965 has a single antennaelement or a plurality of antenna elements, and is used for transmissionand reception of a wireless signal from the wireless communicationinterface 963.

In the wireless access point 950 illustrated in FIG. 18, the wirelesssignal transmission processing unit 205, the access control unit 208,and the wireless signal reception processing unit 211 described withreference to FIG. 2 may be implemented in a wireless communicationinterface 963. Also, at least some of the wireless signal transmissionprocessing unit 205, the access control unit 208, and the wirelesssignal reception processing unit 211 may be implemented in a controller951. For example, the wireless signal transmission processing unit 205converts a baseband signal into a high-frequency signal. The accesscontrol unit 208 controls access of communication on the wirelesstransmission path according to a predetermined wireless communicationprotocol. Further, the wireless signal reception processing unit 211extracts the baseband signal from the high-frequency signal.

6. Conclusion

As described above, according to the embodiments of the presentdisclosure, there is provided a transmission control device thatincludes a communication control unit that controls transmission of aplurality of pieces of data including respective sequence numbers, and adata generation unit that generates, as information indicating one or aplurality of pieces of data to be processed in a reception device amongthe plurality of pieces of data, number information indicating thesequence numbers included in the one or plurality of pieces of data tobe processed, in which the communication control unit controlstransmission of the number information to the reception device.

According to the configuration, even when a sequence number space isshared among the plurality of pieces of multicast data transmitted fromthe transmission-side communication device, predetermined processing canbe performed on desired data in the reception-side communication device.

Further, by using flush information, when a sequence number of atransmission-side communication device is shared for multicastcommunication, data received by a reception-side communication devicemay be flushed from a buffer. The transmission-side communication devicemay transmit a flush frame for each multicast flow and manage a singlesequence number space for multicast communication of a plurality ofother flows. Also, the reception-side communication device can simplifya management method of a sequence number of desired multicastcommunication, which is designated as destination itself.

The reception-side communication device can easily separate pieces ofdata sent using the same sequence number in the data frame and themanagement frame. Also, even when the reception-side communicationdevice receives flush information which is not required by itself, thereception-side communication device can easily grasp the latest sequencenumbers thereof. By defining a flush frame in which flush information isdefined, when the reception-side communication device receives a flushframe of a flow designated as a destination itself, the reception-sidecommunication device can flush received data from a buffer withoutwaiting for a predetermined timeout time.

By defining a flush information element for a beacon signal, thereception-side communication device can flush a multicast frame to becollected by itself even when the reception-side communication devicereceives a multicast frame used in another adjacent network. Further, bystoring flush information as header information of a data frame, theflush information can be sent to the reception-side communication devicewithout sending another frame.

The preferred embodiments of the present disclosure have been describedabove with reference to the accompanying drawings, whilst the presentdisclosure is not limited to the above examples. A person skilled in theart may find various alterations and modifications within the scope ofthe appended claims, and it should be understood that they willnaturally come under the technical scope of the present disclosure.

Although a process using the block ACK has been described above as anexample, embodiments of the present disclosure are not limited theretoand can be applied to any delivery confirmation processing.

Further, a program for causing hardware, such as a CPU, ROM and RAMbuilt into a computer, to exhibit functions similar to the functionsincluded in the above described the communication device 10 can becreated. Further, a recording medium can also be provided which recordsthese programs and is capable of performing reading to the computer.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A transmission control device including:

a communication control unit that controls transmission of a pluralityof pieces of data including respective sequence numbers; and

a data generation unit that generates, as information indicating one ora plurality of pieces of data to be processed in a reception deviceamong the plurality of pieces of data, number information indicating thesequence numbers included in the one or plurality of pieces of data tobe processed,

in which the communication control unit controls transmission of thenumber information to the reception device.

(2)

The transmission control device according to (1), in which thecommunication control unit controls transmission of the numberinformation by multi cast communication.

(3)

The transmission control device according to (2), in which the numberinformation is defined for each flow of the multicast communication.

(4)

The transmission control device according to any one of (1) to (3), inwhich the communication control unit controls transmission of amanagement frame including the number information to the receptiondevice.

(5)

The transmission control device according to any one of (1) to (3), inwhich the communication control unit controls transmission of a beaconsignal including the number information to the reception device.

(6)

The transmission control device according to any one of (1) to (3), inwhich the communication control unit controls transmission of a dataframe for which the number information is set in header information tothe reception device.

(7)

A transmission control method including:

controlling transmission of a plurality of pieces of data includingrespective sequence numbers;

generating, as information indicating one or a plurality of pieces ofdata to be processed in a reception device among the plurality of piecesof data, number information indicating the sequence numbers included inthe one or plurality of pieces of data to be processed; and

controlling transmission of the number information to the receptiondevice.

(8)

A reception control device including:

a communication control unit that controls reception, from atransmission device, of number information indicating sequence numbersincluded in one or a plurality of pieces of data to be processed, asinformation indicating the one or plurality of pieces of data to beprocessed among a plurality of pieces of data including respectivesequence numbers; and

a data acquisition unit that acquires the number information.

(9)

The reception control device according to (8), including:

a storage control unit that flushes the one or plurality of pieces ofdata to be processed from a storage area in a case in which it isdetermined that the one or plurality of pieces of data to be processedare received with reference to the number information.

(10)

The reception control device according to (9), in which, in a case inwhich number information for each flow is received, the storage controlunit refers to the number information for each of the flows and, in acase in which it is determined that one or plurality of pieces of datato be processed related to all of the flows are received, flushes theone or plurality of pieces of data to be processed related to all of theflows from the storage area.

(11)

The reception control device according to (9), in which, in a case inwhich number information for each flow is received, the storage controlunit refers to the number information for each of the flows and, in acase in which it is determined that one or plurality of pieces of datato be processed related to some of the flows are received, flushes theone or plurality of pieces of data to be processed related to some ofthe flows from the storage area and does not flush the one or pluralityof pieces of data to be processed related to the rest of the flows.

(12)

The reception control device according to (8), including:

a storage control unit that delivers the one or plurality of pieces ofdata to be processed from a storage area to an upper layer in a case inwhich it is determined that the one or plurality of pieces of data to beprocessed are received with reference to the number information.

(13)

The reception control device according to (8), including:

a storage control unit that flushes received data to be processed from astorage area in a case in which it is determined that reception of theone or plurality of pieces of data to be processed is not completed evenafter a lapse of a predetermined period with reference to the numberinformation.

(14)

A reception control method including:

controlling reception, from a transmission device, of number informationindicating sequence numbers included in one or a plurality of pieces ofdata to be processed, as information indicating the one or plurality ofpieces of data to be processed among a plurality of pieces of dataincluding respective sequence numbers; and

acquiring the number information.

REFERENCE SIGNS LIST

-   1 communication system-   10 communication device-   201 interface unit-   202 transmitting buffer unit-   203 Buffer management unit-   204 transmission data frame construction unit 204-   205 wireless signal transmission processing unit-   206 multicast transmission sequence management unit 206-   207 flush frame construction unit-   208 access control unit-   209 antenna control unit-   210 antenna element-   211 wireless signal reception processing unit-   212 reception data frame extraction unit-   213 receiving buffer unit-   214 flush frame extraction unit-   215 multicast reception sequence management unit

The invention claimed is:
 1. A transmission control device comprisingone or more circuits configured to: control transmission of a pluralityof pieces of data including respective sequence numbers; and generateflush information indicating one or a plurality of the sequence numbersincluded in one or a plurality of pieces of data to be flushed in areception device among the plurality of pieces of data, wherein the oneor more circuits are configured to control transmission of a frame, andthe frame comprises the flush information.
 2. The transmission controldevice according to claim 1, wherein the frame is a management frame. 3.The transmission control device according to claim 1, wherein the frameis a beacon frame.
 4. The transmission control device according to claim1, wherein the frame is an aggregated MAC Protocol Data Unit (A-MPDU)subframe and a flush control header is added to a front or to an end ofthe A-MPDU subframe.
 5. A transmission control method comprising:controlling transmission of a plurality of pieces of data includingrespective sequence numbers; generating flush information indicating oneor a plurality of the sequence numbers included in one or a plurality ofpieces of data to be flushed in a reception device among the pluralityof pieces of data; and controlling transmission of a frame, wherein theframe comprises the flush information.
 6. The transmission controlmethod according to claim 5, wherein the frame is a management frame. 7.The transmission control method according to claim 5, wherein the frameis a beacon frame.
 8. The transmission control method according to claim5, wherein the frame is an aggregated MAC Protocol Data Unit (A-MPDU)subframe and a flush control header is added to a front or to an end ofthe A-MPDU subframe.
 9. A reception control device comprising one ormore circuits configured to: control reception, from a transmissiondevice, of a frame including flush information indicating one or aplurality of sequence numbers included in one or a plurality of piecesof data to be flushed among a plurality of pieces of data includingrespective sequence numbers; and acquire the flush information, whereinthe one or more circuits are configured to flush received data based atleast in part on the flush information in the frame.
 10. The receptioncontrol device according to claim 9, wherein the frame is a managementframe.
 11. The reception control device according to claim 9, whereinthe frame is a beacon frame.
 12. The reception control device accordingto claim 9, wherein the frame is an aggregated MAC Protocol Data Unit(A-MPDU) subframe and a flush control header is added to a front or toan end of the A-MPDU subframe.
 13. A reception control methodcomprising: controlling reception, from a transmission device, of aframe including flush information indicating one or a plurality ofsequence numbers included in one or a plurality of pieces of data to beflushed among a plurality of pieces of data including respectivesequence numbers; acquiring the flush information; and flushing receiveddata based at least in part on the flush information in the frame. 14.The reception control method according to claim 13, wherein the frame isa management frame.
 15. The reception control method according to claim13, wherein the frame is a beacon frame.
 16. The reception controlmethod according to claim 13, wherein the frame is an aggregated MACProtocol Data Unit (A-MPDU) subframe and a flush control header is addedto a front or to an end of the A-MPDU subframe.